I am gettting PCM data from Microphone using AudioRecord class, how to encode it to MP3 using MediaCodec in Android?
Yes it is Possible MediaCodec Reference
Below code will convect pcm to m4a you have to modify muxer output format for mp3
private void convertAudio(String filename) throws IOException {
String outputpath =Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC).getPath()+"/converted.m4a";
// Set up MediaExtractor to read from the source.
MediaExtractor extractor = new MediaExtractor();
extractor.setDataSource(filename);
int trackCount = extractor.getTrackCount();
// Set up MediaMuxer for the destination.
MediaMuxer muxer;
muxer = new MediaMuxer(outputpath, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
// Set up the tracks.
HashMap<Integer, Integer> indexMap = new HashMap<Integer, Integer>(trackCount);
for (int i = 0; i < trackCount; i++) {
extractor.selectTrack(i);
MediaFormat format = extractor.getTrackFormat(i);
format.setString(MediaFormat.KEY_MIME, MediaFormat.MIMETYPE_AUDIO_AMR_NB);
int dstIndex = muxer.addTrack(format);
indexMap.put(i, dstIndex);
}
// Copy the samples from MediaExtractor to MediaMuxer.
boolean sawEOS = false;
int bufferSize = 32000;
int frameCount = 0;
int offset = 100;
ByteBuffer dstBuf = ByteBuffer.allocate(bufferSize);
MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
/* if (degrees >= 0) {
muxer.setOrientationHint(degrees);
}*/
// Test setLocation out of bound cases
muxer.start();
while (!sawEOS) {
bufferInfo.offset = offset;
bufferInfo.size = extractor.readSampleData(dstBuf, offset);
if (bufferInfo.size < 0) {
sawEOS = true;
bufferInfo.size = 0;
} else {
bufferInfo.presentationTimeUs = extractor.getSampleTime();
bufferInfo.flags = extractor.getSampleFlags();
int trackIndex = extractor.getSampleTrackIndex();
muxer.writeSampleData(indexMap.get(trackIndex), dstBuf,
bufferInfo);
extractor.advance();
frameCount++;
}
}
muxer.stop();
muxer.release();
return;
}
Related
I have a need to merge multiple mp4 files into a single file. The source files are encoded using the exact same video and audio codecs and parameters. I would like to avoid decoding/encoding the streams in order to merge them. As a test, I tried simply concatenating the raw encoded frames from the source videos using the MediaMuxer, adjusting the presentation times as necessary. It seems to work, the resulting mp4 file is playable on all video players I've tested and FFMPEG seems happy with the merged file. Just wondering if there is an issue that I am not anticipating since I am not an expert on the mp4 file structure. Here is the code I am using:
private static class VideoSegment {
public VideoSegment(File file, long duration, int videoTrackIndex, int audioTrackIndex) {
this.file = file;
this.duration = duration;
this.videoTrackIndex = videoTrackIndex;
this.audioTrackIndex = audioTrackIndex;
}
File file;
long duration;
int videoTrackIndex;
int audioTrackIndex;
}
private File mergeVideoFiles(List<File> files) throws IOException, IllegalArgumentException {
final List<VideoSegment> segments = new ArrayList<>();
int videoRotationHint = 0;
long totalDuration = 0;
MediaFormat sourceVideoFormat = null, sourceAudioFormat = null;
for (int fileIndex = 0; fileIndex < files.size(); fileIndex++) {
final File segmentFile = files.get(fileIndex);
MediaExtractor extractor = new MediaExtractor();
extractor.setDataSource(segmentFile.getAbsolutePath());
int videoTrackIndex = this.getVideoTrackIndex(extractor);
final MediaFormat videoFormat = extractor.getTrackFormat(videoTrackIndex);
if (sourceVideoFormat == null) {
sourceVideoFormat = videoFormat;
videoRotationHint = videoFormat.getInteger(MediaFormat.KEY_ROTATION);
}
long segmentDuration = videoFormat.getLong(MediaFormat.KEY_DURATION);
totalDuration += segmentDuration;
int audioTrackIndex = this.getAudioTrackIndex(extractor);
if (sourceAudioFormat == null) {
sourceAudioFormat = extractor.getTrackFormat(audioTrackIndex);
}
segments.add(new VideoSegment(segmentFile, segmentDuration, videoTrackIndex, audioTrackIndex));
extractor.release();
}
// simply create a copy of the video and audio formats, then adjust the duration
final MediaFormat outputVideoFormat = new MediaFormat(sourceVideoFormat);
final MediaFormat outputAudioFormat = new MediaFormat(sourceAudioFormat);
outputVideoFormat.setLong(MediaFormat.KEY_DURATION, totalDuration);
outputAudioFormat.setLong(MediaFormat.KEY_DURATION, totalDuration);
final File mergedFile = new File(this.reactContext.getApplicationContext().getExternalFilesDir(null), "merged.mp4");
final MediaMuxer muxer = new MediaMuxer(mergedFile.getPath(), MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
int outputVideoTrackIndex = muxer.addTrack(outputVideoFormat);
int outputAudioTrackIndex = muxer.addTrack(outputAudioFormat);
muxer.setOrientationHint(videoRotationHint);
muxer.start();
long segmentOffset = 0;
for (int segmentIndex = 0; segmentIndex < segments.size(); segmentIndex++) {
final VideoSegment segment = segments.get(segmentIndex);
MediaExtractor extractor = new MediaExtractor();
extractor.setDataSource(segment.file.getAbsolutePath());
extractor.selectTrack(segment.videoTrackIndex);
this.copyTrackData(extractor, muxer, segmentOffset, outputVideoTrackIndex);
extractor.selectTrack(segment.audioTrackIndex);
this.copyTrackData(extractor, muxer, segmentOffset, outputAudioTrackIndex);
extractor.release();
segmentOffset += segment.duration;
};
muxer.stop();
muxer.release();
return mergedFile;
}
private void copyTrackData(final MediaExtractor extractor, final MediaMuxer muxer, final long startOffset, final int outputTrackIndex) throws IllegalArgumentException {
MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
ByteBuffer inputBuffer = ByteBuffer.allocate(1024 * 1024);
int bytesRead = 0;
boolean moreFrames = true;
do {
bytesRead = extractor.readSampleData(inputBuffer, 0);
bufferInfo.presentationTimeUs = startOffset + extractor.getSampleTime();
bufferInfo.flags = extractor.getSampleFlags();
bufferInfo.size = bytesRead;
if (bytesRead > 0) {
muxer.writeSampleData(outputTrackIndex, inputBuffer, bufferInfo);
moreFrames = extractor.advance();
} else {
moreFrames = false;
}
} while (moreFrames);
}
In my Android App I need a solution when the user can trim a video from internal storage. I am trying to achieve this without using any third-party library. I was referencing this Google's Gallery App source code here. But I am getting the following error :
timestampUs 66733 < lastTimestampUs 133467 for Video track
There are few SO questions which talk about this timestamp issue, but I am really not being to figure out as I am new to using MediaCodecs, MediaMuxers etc. Would be great if any can hep
Here's my code :
// Set up MediaExtractor to read from the source.
MediaExtractor extractor = new MediaExtractor();
extractor.setDataSource(srcPath);
int trackCount = extractor.getTrackCount();
System.out.println("tracl" + trackCount);
// Set up MediaMuxer for the destination.
MediaMuxer muxer;
muxer = new MediaMuxer(dstPath, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
// Set up the tracks and retrieve the max buffer size for selected
// tracks.
HashMap<Integer, Integer> indexMap = new HashMap<>(trackCount);
int bufferSize = -1;
for (int i = 0; i < trackCount; i++) {
MediaFormat format = extractor.getTrackFormat(i);
String mime = format.getString(MediaFormat.KEY_MIME);
boolean selectCurrentTrack = false;
if (mime.startsWith("audio/") && useAudio) {
selectCurrentTrack = true;
} else if (mime.startsWith("video/") && useVideo) {
selectCurrentTrack = true;
}
if (selectCurrentTrack) {
extractor.selectTrack(i);
int dstIndex = muxer.addTrack(format);
System.out.println(format);
System.out.println("dstIndex" + dstIndex);
indexMap.put(i, dstIndex);
if (format.containsKey(MediaFormat.KEY_MAX_INPUT_SIZE)) {
int newSize = format.getInteger(MediaFormat.KEY_MAX_INPUT_SIZE);
bufferSize = newSize > bufferSize ? newSize : bufferSize;
}
}
}
System.out.println(indexMap);
if (bufferSize < 0) {
bufferSize = DEFAULT_BUFFER_SIZE;
}
// Set up the orientation and starting time for extractor.
MediaMetadataRetriever retrieverSrc = new MediaMetadataRetriever();
retrieverSrc.setDataSource(srcPath);
String degreesString = retrieverSrc.extractMetadata(
MediaMetadataRetriever.METADATA_KEY_VIDEO_ROTATION);
if (degreesString != null) {
int degrees = Integer.parseInt(degreesString);
if (degrees >= 0) {
muxer.setOrientationHint(degrees);
}
}
if (startMs > 0) {
extractor.seekTo(startMs * 1000, MediaExtractor.SEEK_TO_CLOSEST_SYNC);
}
// System.out.println(extractor.);
// Copy the samples from MediaExtractor to MediaMuxer. We will loop
// for copying each sample and stop when we get to the end of the source
// file or exceed the end time of the trimming.
int offset = 0;
int trackIndex = -1;
ByteBuffer dstBuf = ByteBuffer.allocate(bufferSize);
MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
try {
muxer.start();
while (true) {
System.out.println("copying");
bufferInfo.offset = offset;
bufferInfo.size = extractor.readSampleData(dstBuf, offset);
if (bufferInfo.size < 0 ) {
// InstabugSDKLogger.d(TAG, "Saw input EOS.");
System.out.println("Saw input EOS.");
bufferInfo.size = 0;
break;
} else {
/**
* The presentation timestamp in microseconds for the buffer.
* This is derived from the presentation timestamp passed in
* with the corresponding input buffer. This should be ignored for
* a 0-sized buffer.
*/
/**
* Returns the current sample's presentation time in microseconds.
* or -1 if no more samples are available.
*/
bufferInfo.presentationTimeUs = extractor.getSampleTime();
//1 sec = 1000000 micco sec
if (endMs > 0 && bufferInfo.presentationTimeUs > (endMs * 1000)) {
break;
} else {
bufferInfo.flags = extractor.getSampleFlags();
trackIndex = extractor.getSampleTrackIndex();
muxer.writeSampleData(indexMap.get(trackIndex), dstBuf, bufferInfo);
//System.out.println(muxer);
extractor.advance();
}
}
}
muxer.stop();
File file = new File(srcPath);
file.delete();
} catch (IllegalStateException e) {
System.out.println("The source video file is malformed");
} finally {
muxer.release();
}
I'm developing an Android App with mp3 audio file and mp4 video file with(no sound).
Now I want to mix them and create a new mp4 video file(with sound). From Android 4.3, Google suggests using the MediaMuxer class to mix stream audio and video. I have tried many times without success.
Here is the code:
private void muxing() {
String outputFile = "";
try {
File file = new File(Environment.getExternalStorageDirectory() + "/final2.mp4");
file.createNewFile();
outputFile = file.getAbsolutePath();
MediaExtractor videoExtractor = new MediaExtractor();
videoExtractor.setDataSource(Environment.getExternalStorageDirectory().toString()+"/vd1.h264");
MediaExtractor audioExtractor = new MediaExtractor();
audioExtractor.setDataSource(Environment.getExternalStorageDirectory()+"/audioVideoDir/audio.m4a");
MediaMuxer muxer = new MediaMuxer(outputFile, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
videoExtractor.selectTrack(0);
MediaFormat videoFormat = videoExtractor.getTrackFormat(0);
int videoTrack = muxer.addTrack(videoFormat);
audioExtractor.selectTrack(0);
MediaFormat audioFormat = audioExtractor.getTrackFormat(0);
int audioTrack = muxer.addTrack(audioFormat);
boolean sawEOS = false;
int frameCount = 0;
int offset = 100;
int sampleSize = 256 * 1024;
ByteBuffer videoBuf = ByteBuffer.allocate(sampleSize);
ByteBuffer audioBuf = ByteBuffer.allocate(sampleSize);
MediaCodec.BufferInfo videoBufferInfo = new MediaCodec.BufferInfo();
MediaCodec.BufferInfo audioBufferInfo = new MediaCodec.BufferInfo();
videoExtractor.seekTo(0, MediaExtractor.SEEK_TO_CLOSEST_SYNC);
audioExtractor.seekTo(0, MediaExtractor.SEEK_TO_CLOSEST_SYNC);
muxer.start();
while (!sawEOS)
{
videoBufferInfo.offset = offset;
videoBufferInfo.size = videoExtractor.readSampleData(videoBuf, offset);
if (videoBufferInfo.size < 0 || audioBufferInfo.size < 0)
{
// Log.d(TAG, "saw input EOS.");
sawEOS = true;
videoBufferInfo.size = 0;
}
else
{
videoBufferInfo.presentationTimeUs = videoExtractor.getSampleTime();
videoBufferInfo.flags = videoExtractor.getSampleFlags();
muxer.writeSampleData(videoTrack, videoBuf, videoBufferInfo);
videoExtractor.advance();
frameCount++;
}
}
Toast.makeText(getApplicationContext() , "frame:" + frameCount , Toast.LENGTH_SHORT).show();
boolean sawEOS2 = false;
int frameCount2 =0;
while (!sawEOS2)
{
frameCount2++;
audioBufferInfo.offset = offset;
audioBufferInfo.size = audioExtractor.readSampleData(audioBuf, offset);
if (videoBufferInfo.size < 0 || audioBufferInfo.size < 0)
{
// Log.d(TAG, "saw input EOS.");
sawEOS2 = true;
audioBufferInfo.size = 0;
}
else
{
audioBufferInfo.presentationTimeUs = audioExtractor.getSampleTime();
audioBufferInfo.flags = audioExtractor.getSampleFlags();
muxer.writeSampleData(audioTrack, audioBuf, audioBufferInfo);
audioExtractor.advance();
}
}
Toast.makeText(getApplicationContext() , "frame:" + frameCount2 , Toast.LENGTH_SHORT).show();
muxer.stop();
muxer.release();
} catch (IOException e) {
} catch (Exception e) {
}
}
I get the below error:
Unknown mime type 'audio/mpeg'. 12-09 11:58:33.569: A/MPEG4Writer(332): frameworks/av/media/libstagefright/MPEG4Writer.cpp:2699 CHECK(!"should not be here, unknown mime type.")
Any solution to resolve my issue with MediaMuxer API from Google? Even i tried with ffmpeg after merging of audio and video together video doesn't plays in default video player of android device but it loads in Vlc player.
FFMPEG followed from here:https://github.com/WritingMinds/ffmpeg-android-java
try to add mp4 video file.
Its working for me. but output file is with audio duration.
I have the following function which takes a WAV (PCM) file and encodes it to an AAC-encoded MP4 file using Android's MediaCode and MediaMuxer classes. This is audio only. The function runs successfully and outputs a .mp4 of reasonable that is recognized as AAC-encoded. But it doesn't play on Android, web or iOS players, and crashes Audacity. Is there something I am missing? Code is shown below.
public void encode(final String from, final String to, final Callback callback) {
new Thread(new Runnable() {
#Override
public void run() {
try {
extractor.setDataSource(from);
int numTracks = extractor.getTrackCount();
for (int i = 0; i < numTracks; ++i) {
MediaFormat format = extractor.getTrackFormat(i);
String mime = format.getString(MediaFormat.KEY_MIME);
Log.d(TAG, "Track " + i + " mime-type: " + mime);
if (true) {
extractor.selectTrack(i);
}
}
MediaCodec codec = MediaCodec.createEncoderByType("audio/mp4a-latm");
MediaFormat format = new MediaFormat();
format.setString(MediaFormat.KEY_MIME, "audio/mp4a-latm");
format.setInteger(MediaFormat.KEY_BIT_RATE, 128 * 1024);
format.setInteger(MediaFormat.KEY_CHANNEL_COUNT, 2);
format.setInteger(MediaFormat.KEY_SAMPLE_RATE, 44100);
format.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
codec.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
final MediaMuxer muxer = new MediaMuxer(to, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
final ByteBuffer byteBuffer = ByteBuffer.allocate(65536);
codec.setCallback(new MediaCodec.Callback() {
#Override
public void onInputBufferAvailable(MediaCodec codec, int bufferIndex) {
ByteBuffer inputBuffer = codec.getInputBuffer(bufferIndex);
if (isEndOfStream) {
return;
}
int sampleCapacity = inputBuffer.capacity() / 8;
if (numAvailable == 0) {
numAvailable = extractor.readSampleData(byteBuffer, 0);
if (numAvailable <= 0) {
codec.queueInputBuffer(bufferIndex, 0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
isEndOfStream = true;
return;
}
long presentationTimeUs = extractor.getSampleTime();
extractor.advance();
}
if (numAvailable < sampleCapacity) {
codec.queueInputBuffer(bufferIndex, 0, numAvailable * 8, 0, 0);
numAvailable = 0;
} else {
codec.queueInputBuffer(bufferIndex, 0, sampleCapacity * 8, 0, 0);
numAvailable -= sampleCapacity;
}
}
#Override
public void onOutputBufferAvailable(MediaCodec codec, int index, MediaCodec.BufferInfo info) {
ByteBuffer outputBuffer = codec.getOutputBuffer(index);
muxer.writeSampleData(audioTrackIndex,outputBuffer,info);
codec.releaseOutputBuffer(index, true);
if ((info.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
Log.d(TAG, "end of encoding!");
codec.stop();
codec.release();
extractor.release();
extractor = null;
muxer.stop();
muxer.release();
callback.run(true);
}
}
#Override
public void onError(MediaCodec codec, MediaCodec.CodecException e) {
Log.e(TAG, "codec error", e);
}
#Override
public void onOutputFormatChanged(MediaCodec codec, MediaFormat format) {
audioTrackIndex = muxer.addTrack(format);
muxer.start();
}
});
codec.start();
} catch (IOException e) {
Log.e(TAG,"Unable to encode",e);
callback.run(false);
}
}
}).run();
You need to:
Add timestamp information correctly since media muxer need to use it to TAG packet time information.
Add logic to copy data buffer from extractor data buffer (PCM) to mediacodec input buffer, only refer to buffer index will only encode a random data buffer without initial.
Add code to apply input source property such as channels and sample rate to mediacodec. Not sure if you are intent to encode with different channels and sample rate!
Example code as below:
MediaExtractor extractor = null;
int numAvailable = 0;
boolean isEndOfStream = false;
int audioTrackIndex = 0;
long totalen = 0;
int channels = 0;
int sampleRate = 0;
public void encode(final String from, final String to) {
new Thread(new Runnable() {
#Override
public void run() {
try {
extractor = new MediaExtractor();
extractor.setDataSource(from);
int numTracks = extractor.getTrackCount();
for (int i = 0; i < numTracks; ++i) {
MediaFormat format = extractor.getTrackFormat(i);
String mime = format.getString(MediaFormat.KEY_MIME);
Log.d(TAG, "Track " + i + " mime-type: " + mime);
if (true) {
extractor.selectTrack(i);
channels = extractor.getTrackFormat(i).getInteger(MediaFormat.KEY_CHANNEL_COUNT);
sampleRate = extractor.getTrackFormat(i).getInteger(MediaFormat.KEY_SAMPLE_RATE);
Log.e(TAG,"sampleRate:" + sampleRate + " channels:" + channels);
}
}
String mimeType = "audio/mp4a-latm";
MediaCodec codec = MediaCodec.createEncoderByType(mimeType);
MediaFormat format = new MediaFormat();
format.setString(MediaFormat.KEY_MIME, mimeType);
format.setInteger(MediaFormat.KEY_BIT_RATE, 128 * 1024);
format.setInteger(MediaFormat.KEY_CHANNEL_COUNT, channels);
format.setInteger(MediaFormat.KEY_SAMPLE_RATE, sampleRate);
format.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
codec.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
final MediaMuxer muxer = new MediaMuxer(to, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
final ByteBuffer byteBuffer = ByteBuffer.allocate(65536);
codec.setCallback(new MediaCodec.Callback() {
#Override
public void onInputBufferAvailable(MediaCodec codec, int bufferIndex) {
ByteBuffer inputBuffer = codec.getInputBuffer(bufferIndex);
inputBuffer.clear();
if (isEndOfStream) {
return;
}
int sampleCapacity = inputBuffer.capacity();
if (numAvailable == 0) {
numAvailable = extractor.readSampleData(byteBuffer, 0);
if (numAvailable <= 0) {
codec.queueInputBuffer(bufferIndex, 0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
isEndOfStream = true;
return;
}
extractor.advance();
}
long timestampUs = 1000000l * totalen / (2 * channels * sampleRate);
if (numAvailable < sampleCapacity) {
byte[] byteArray = new byte[numAvailable];
byteBuffer.get(byteArray);
inputBuffer.put(byteArray, 0, (int)numAvailable);
totalen += numAvailable;
codec.queueInputBuffer(bufferIndex, 0, numAvailable, timestampUs, 0);
numAvailable = 0;
} else {
byte[] byteArray = new byte[sampleCapacity];
byteBuffer.get(byteArray);
inputBuffer.put(byteArray, 0, (int)sampleCapacity);
totalen += sampleCapacity;
codec.queueInputBuffer(bufferIndex, 0, sampleCapacity, timestampUs, 0);
numAvailable -= sampleCapacity;
}
}
#Override
public void onOutputBufferAvailable(MediaCodec codec, int index, MediaCodec.BufferInfo info) {
ByteBuffer outputBuffer = codec.getOutputBuffer(index);
muxer.writeSampleData(audioTrackIndex,outputBuffer,info);
codec.releaseOutputBuffer(index, true);
if ((info.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
Log.d(TAG, "end of encoding!");
codec.stop();
codec.release();
extractor.release();
extractor = null;
muxer.stop();
muxer.release();
//callback.run(true);
}
}
#Override
public void onError(MediaCodec codec, MediaCodec.CodecException e) {
Log.e(TAG, "codec error", e);
}
#Override
public void onOutputFormatChanged(MediaCodec codec, MediaFormat format) {
audioTrackIndex = muxer.addTrack(format);
muxer.start();
}
});
codec.start();
} catch (IOException e) {
Log.e(TAG,"Unable to encode",e);
//callback.run(false);
}
}
}).run();
}
BTW,Why you need to divide 8 with the buffer length? And what's the Callback class? Please share the import module! I almost can not pass build with the callback parameter so comment it out!
You seem to be encoding your AAC into LATM format which isn't very popular. Maybe that's the reason players won't play it. Try using some other media type, audio/mp4 or audio/3gpp.
See AAC container formats.
I want to play static HLS content (not live video content) on my app in Android. What I currently do is download all the segments from the .m3u8 file and merge it into one file. When I play this file, I can see this the video being played, but it is not seekable. As per this link, .ts files are not seekable on Android.
I cannot risk running ffmpeg on phone for converting the file to MP4 format. I have studied MP4 format and its atom structure. What I want to know is, if there is an easy way to create MP4 container (atoms hierarchy) which would simply refer to the .ts segment (the merged segment that was created from sub-segments) in its data atom (mdat)
I would really appreciate any help/suggestions.
Not possible without a copy. TS is uses 188 byte packets with headers. These headers create breaks in the middle of frames. In mp4, frames must be contiguous.
Android provides support libraries such as MediaCodec and MediaExtractor that provides access to low level media encoding/decoding. It is fast and efficient as it uses hardware acceleration.
Here's how I believe one is suppose to do it on Android unless you are ok with using ffmpeg which of course if resource intensive operation.
1) Use MediaExtractor to extract data from the file.
2) Pass the extracted data to MediaCodec.
3) Use MediaCodec to render output to a surface (in case of video) and AudioTrack (in case of audio).
4) This is the most difficult step: Synchronize audio/video. I haven't implemented this yet. But this would require keeping track of time sync between audio and video. Audio would be played normally and you might have to drop some frames in case of video to keep it in sync with audio playback.
Here's code for decoding audio/video and playing them respectively using AudioTrack and Surface.
In case of video decoding, there's a sleep to slowdown the frame rendering.
public void decodeVideo(Surface surface) throws IOException {
MediaExtractor extractor = new MediaExtractor();
MediaCodec codec;
ByteBuffer[] codecInputBuffers;
ByteBuffer[] codecOutputBuffers;
extractor.setDataSource(file);
Log.d(TAG, "No of tracks = " + extractor.getTrackCount());
MediaFormat format = extractor.getTrackFormat(0);
String mime = format.getString(MediaFormat.KEY_MIME);
Log.d(TAG, "mime = " + mime);
Log.d(TAG, "format = " + format);
codec = MediaCodec.createDecoderByType(mime);
codec.configure(format, surface, null, 0);
codec.start();
codecInputBuffers = codec.getInputBuffers();
codecOutputBuffers = codec.getOutputBuffers();
extractor.selectTrack(0);
final long timeout_in_Us = 5000;
MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();
boolean sawInputEOS = false;
boolean sawOutputEOS = false;
int noOutputCounter = 0;
long startMs = System.currentTimeMillis();
while(!sawOutputEOS && noOutputCounter < 50) {
noOutputCounter++;
if(!sawInputEOS) {
int inputBufIndex = codec.dequeueInputBuffer(timeout_in_Us);
if(inputBufIndex >= 0) {
ByteBuffer dstBuf = codecInputBuffers[inputBufIndex];
int sampleSize = extractor.readSampleData(dstBuf, 0);
long presentationTimeUs = 0;
if(sampleSize < 0) {
Log.d(TAG, "saw input EOS.");
sawInputEOS = true;
sampleSize = 0;
} else {
presentationTimeUs = extractor.getSampleTime();
}
codec.queueInputBuffer(inputBufIndex, 0, sampleSize, presentationTimeUs, sawInputEOS ? MediaCodec.BUFFER_FLAG_END_OF_STREAM : 0);
if(!sawInputEOS) {
extractor.advance();
}
}
}
int res = codec.dequeueOutputBuffer(info, timeout_in_Us);
if(res >= 0) {
if(info.size > 0) {
noOutputCounter = 0;
}
int outputBufIndex = res;
while(info.presentationTimeUs/1000 > System.currentTimeMillis() - startMs) {
try {
Thread.sleep(5);
} catch (Exception e) {
break;
}
}
codec.releaseOutputBuffer(outputBufIndex, true);
if((info.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) == MediaCodec.BUFFER_FLAG_END_OF_STREAM) {
Log.d(TAG, "saw output EOS.");
sawOutputEOS = true;
}
} else if(res == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
codecOutputBuffers = codec.getOutputBuffers();
Log.d(TAG, "output buffers have changed.");
} else if(res == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
MediaFormat format1 = codec.getOutputFormat();
Log.d(TAG, "output format has changed to " + format1);
} else if(res == MediaCodec.INFO_TRY_AGAIN_LATER) {
Log.d(TAG, "Codec try again returned" + res);
}
}
codec.stop();
codec.release();
}
private int audioSessionId = -1;
private AudioTrack createAudioTrack(MediaFormat format) {
int channelConfiguration = format.getInteger(MediaFormat.KEY_CHANNEL_COUNT) == 1 ? AudioFormat.CHANNEL_OUT_MONO : AudioFormat.CHANNEL_OUT_STEREO;
int bufferSize = AudioTrack.getMinBufferSize(format.getInteger(MediaFormat.KEY_SAMPLE_RATE), channelConfiguration, AudioFormat.ENCODING_PCM_16BIT) * 8;
AudioTrack audioTrack;
if(audioSessionId == -1) {
audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, format.getInteger(MediaFormat.KEY_SAMPLE_RATE), channelConfiguration,
AudioFormat.ENCODING_PCM_16BIT, bufferSize, AudioTrack.MODE_STREAM);
} else {
audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, format.getInteger(MediaFormat.KEY_SAMPLE_RATE), channelConfiguration,
AudioFormat.ENCODING_PCM_16BIT, bufferSize, AudioTrack.MODE_STREAM, audioSessionId);
}
audioTrack.play();
audioSessionId = audioTrack.getAudioSessionId();
return audioTrack;
}
public void decodeAudio() throws IOException {
MediaExtractor extractor = new MediaExtractor();
MediaCodec codec;
ByteBuffer[] codecInputBuffers;
ByteBuffer[] codecOutputBuffers;
extractor.setDataSource(file);
Log.d(TAG, "No of tracks = " + extractor.getTrackCount());
MediaFormat format = extractor.getTrackFormat(1);
String mime = format.getString(MediaFormat.KEY_MIME);
Log.d(TAG, "mime = " + mime);
Log.d(TAG, "format = " + format);
codec = MediaCodec.createDecoderByType(mime);
codec.configure(format, null, null, 0);
codec.start();
codecInputBuffers = codec.getInputBuffers();
codecOutputBuffers = codec.getOutputBuffers();
extractor.selectTrack(1);
AudioTrack audioTrack = createAudioTrack(format);
final long timeout_in_Us = 5000;
MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();
boolean sawInputEOS = false;
boolean sawOutputEOS = false;
int noOutputCounter = 0;
while(!sawOutputEOS && noOutputCounter < 50) {
noOutputCounter++;
if(!sawInputEOS) {
int inputBufIndex = codec.dequeueInputBuffer(timeout_in_Us);
if(inputBufIndex >= 0) {
ByteBuffer dstBuf = codecInputBuffers[inputBufIndex];
int sampleSize = extractor.readSampleData(dstBuf, 0);
long presentationTimeUs = 0;
if(sampleSize < 0) {
Log.d(TAG, "saw input EOS.");
sawInputEOS = true;
sampleSize = 0;
} else {
presentationTimeUs = extractor.getSampleTime();
}
codec.queueInputBuffer(inputBufIndex, 0, sampleSize, presentationTimeUs, sawInputEOS ? MediaCodec.BUFFER_FLAG_END_OF_STREAM : 0);
if(!sawInputEOS) {
extractor.advance();
}
}
}
int res = codec.dequeueOutputBuffer(info, timeout_in_Us);
if(res >= 0) {
if(info.size > 0) {
noOutputCounter = 0;
}
int outputBufIndex = res;
//Possibly store the decoded buffer
ByteBuffer buf = codecOutputBuffers[outputBufIndex];
final byte[] chunk = new byte[info.size];
buf.get(chunk);
buf.clear();
if(chunk.length > 0) {
audioTrack.write(chunk, 0 ,chunk.length);
}
codec.releaseOutputBuffer(outputBufIndex, false);
if((info.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) == MediaCodec.BUFFER_FLAG_END_OF_STREAM) {
Log.d(TAG, "saw output EOS.");
sawOutputEOS = true;
}
} else if(res == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
codecOutputBuffers = codec.getOutputBuffers();
Log.d(TAG, "output buffers have changed.");
} else if(res == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
MediaFormat format1 = codec.getOutputFormat();
Log.d(TAG, "output format has changed to " + format1);
audioTrack.stop();
audioTrack = createAudioTrack(codec.getOutputFormat());
} else if(res == MediaCodec.INFO_TRY_AGAIN_LATER) {
Log.d(TAG, "Codec try again returned" + res);
}
}
codec.stop();
codec.release();
}